He teats (a)/ us as (b)/ slaves.(c)/ No error (d)

Read each sentence to find out whether there is any grammatical error in it. The error, if any, will be in one part of the sentence, the letter of that part is the answer. If there is no error, then the answer is ( e ). (Ignore the errors of punctuation, if any) When he (a)/ had got what (b)/ the wanted (c)/ he has gone home. (d)/ No error (e)